Effect of surface potential on extracellular matrix protein adsorption.

Extracellular matrix (ECM) proteins, such as fibronectin, laminin, and collagen IV, play important roles in many cellular behaviors, including cell adhesion and spreading. Understanding their adsorption behavior on surfaces with different natures is helpful for studying the cellular responses to environments. By tailoring the chemical composition in binary acidic (anionic) and basic (cationic) functionalized self-assembled monolayer (SAM)-modified gold substrates, variable surface potentials can be generated. To examine how surface potential affects the interaction between ECM proteins and substrates, a quartz crystal microbalance with dissipation detection (QCM-D) was used. To study the interaction under physiological conditions, the ionic strength and pH were controlled using phosphate-buffered saline at 37 °C, and the ζ potentials of the SAM-modified Au and protein were determined using an electrokinetic analyzer and phase analysis light scattering, respectively. During adsorption processes, the shifts...